lcd.c

fat文件系统的源码 老外写的FAT32文件系统 还是有用的

/*
  Copyright (C) 2001 Jesper Hansen <[e-mail]>.

  Rewritten by:	Nikolai Vorontsov <[e-mail]>

  This file is part of the yampp system.

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License
  as published by the Free Software Foundation; either version 2
  of the License, or (at your option) any later version.

  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.

  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software Foundation, 
  Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
*/


#include <io.h>
#include <progmem.h>

#include "lcd.h"
#include "mem.h"
#include "delay.h"

#ifdef ENABLE_LCD

static u08 lcd_x, lcd_y;

/*************************************************************/
/********************** LOCAL FUNCTIONS **********************/
/*************************************************************/

static u08 LCDSetAddress(u08 adr) 
{ 
#ifdef YAMPP3USB
	cbi(MCUCR,SRE);				// disable ExtRAM
	outp(0xff, DDRA);			// set port as output
	outp(adr,  PORTA);			// write addres
	sbi(PORTE,PE1);
	cbi(PORTE,PE1);				// flip ALE
	return 0;
#else
	register u08 b = *(volatile u08 *)(0x8000 | adr);	
	cbi(MCUCR,SRE);				// disable ExtRAM
	return b;				// dummy return to avoid compiler warning
#endif
}


static void lcd_waitbusy(void)				// loops while lcd is busy 
{							// no watchdog in this function
	register u08 i = 0;				// should work fast enough 
	register u08 data;

	// setup RS and RW pins
   	LCDSetAddress(LCD_IO_FUNCTION | LCD_IO_READ);
	outp(0x00, DDR(LCD_DATA_PORT));			// set port as input
	outp(0xff, LCD_DATA_PORT);			// enable pullup
	do
	{
		lcd_e_high();				// set LCD enable high
		data = inp(PIN(LCD_DATA_PORT));		// read byte
		lcd_e_low();				// set LCD enable low
		i++;
	} while ((data & (1 << LCD_BUSY)) && (i != 255));
	enable_ram();					// enable ExtRAM
}


static void lcd_write(u08 data, u08 rs) 
{
	lcd_waitbusy();
	// setup RS and RW pins
   	LCDSetAddress(rs | LCD_IO_WRITE);
	outp(0xff, DDR(LCD_DATA_PORT));		// set port as output
	outp(data, LCD_DATA_PORT);		// write byte
	lcd_e_high();				// set LCD enable high
	lcd_e_low();				// set LCD enable low
	enable_ram();				// enable ExtRAM
}


static void lcd_newline(void)		// goto start of next line
{
    lcd_x = 0;
    if (lcd_y < LCD_LINES)
        lcd_y++;
}


void lcd_goto(void) 		// goto position (lcd_x,lcd_y)
{

#if (LCD_LINE_LENGTH == 16)
 static	u08 lcd_line[] = {0x00, 0x40, 0x10, 0x50};
#else
 static	u08 lcd_line[] = {0x00, 0x40, 0x14, 0x54};
#endif
	lcd_command((1 << LCD_DDRAM) + lcd_line[lcd_y] + lcd_x);
}



/*************************************************************/
/********************* PUBLIC FUNCTIONS **********************/
/*************************************************************/


void lcd_command(u08 cmd)			// send commando <cmd> to LCD 
{
	lcd_write(cmd, LCD_IO_FUNCTION);
}


void lcd_data(u08 data)				// send data <data> to LCD
{
	lcd_write(data, LCD_IO_DATA);
}


void lcd_gotoxy(u08 x, u08 y)		// goto position (x,y) 
{
	lcd_x = x;  lcd_y = y;
	lcd_goto();
}


void lcd_clrscr(void)				// clear lcd
{
	lcd_x = lcd_y = 0;
	lcd_command(1 << LCD_CLR);
	delay10(300);					// 3 ms delay
}


#ifdef ENABLE_LCD_HOME_COMMAND
void lcd_home(void)					// set cursor
{									//  to home position
	lcd_x = lcd_y = 0;
	lcd_command(1 << LCD_HOME);
	delay10(200);					// 2 ms delay
}
#endif


void lcd_putchar(u08 data)			// print character to
{						//  current cursor position
	if (data == '\n')
	{
		lcd_newline();
		lcd_goto();
	}
	else
	{
		if (lcd_x < LCD_LINE_LENGTH)
		{
			lcd_x++;
			lcd_write(data, LCD_IO_DATA);
		}
	}
}


void lcd_puts(u08* str)				// print string on lcd 
{						//  (no auto linefeed)
	while (*str)
		lcd_putchar(*str++);
}

void lcd_puts_p(u08* p)				// print string from flash on lcd 
{	
	register u08 b;
		while ((b = PRG_RDB(p++)))
			lcd_putchar(b);
}


static u16 wait[] = {7,7,500,1600};

         
#endif

// cursor:   0 = off, 2 = on, 3 = blinking
// fnc: see LCD_FUNCTION_xxx
void lcd_init(u08 cursor, u08 fnc)
{
#ifdef ENABLE_LCD
	register u08 i = 3;

	fnc |= (1 << LCD_FUNCTION);

	do						// reset lcd
	{
		delay10(wait[i]);			// 16ms, 5ms, 70us, 70us
		lcd_write(fnc, LCD_IO_FUNCTION);	// reset function
	} while (i--);

	lcd_command(1 << LCD_ON);
	lcd_clrscr();
	lcd_command(LCD_MODE_DEFAULT);
	lcd_command((1 << LCD_ON)|(1 << LCD_ON_DISPLAY) | cursor);
#endif
}